US4726984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxygen barrier oriented film
Assignee: Cryovac LLC
•
Filing: 1985-06-28
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Granted: 1988-02-23
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Expires: 2005-06-28
Abstract
Abstract A coextruded multiple layer oriented film is provided which comprises a core layer of ethylene vinyl alcohol copolymer, two intermediate adhesive layers, and two outer layers of a blend of ethylene propylene copolymer and polypropylene. A preferred embodiment of the multi-layer film exhibits excellent optical properties, and shrink properties while providing high oxygen barrier especially useful in food packaging applications.
Inventors
- 👤 Gautam P. Shah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:21
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/08; B32B27/30; B32B27/306; B32B38/00; B32B38/0036; B32B7/00; B32B7/04; B32B7/12; B32B38/0012; B32B2038/0028; B32B2553/00; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
73 words
A coextruded thermoplastic multi-layer oriented packaging shrink film comprising: (a) a core layer comprising ethylene vinyl alcohol copolymer; (b) two intermediate layers, on opposite surfaces of the core layer, comprising polymeric adhesive; (c) two outer layers disposed on respective surfaces of the intermediate layers, opposite the core layer, and comprising a blend of ethylene propylene copolymer and polypropylene; and (d) said film having a total thickness ranging from about 0.5 to 4 mils.
Claim 2
Dependent Claim
73 words
A coextruded thermoplastic multi-layer oriented packaging shrink film comprising: (a) a core layer comprising ethylene vinyl alcohol copolymer; (b) two intermediate layers, on opposite surfaces of the core layer, comprising polymeric adhesive; (c) two outer layers disposed on respective surfaces of the intermediate layers, opposite the core layer, and comprising a blend of ethylene propylene copolymer and polypropylene; and (d) said film having a total thickness ranging from about 0.5 to 4 mils.
Claim 3
Dependent Claim
21 words
The film in accordance with claim 1 wherein polypropylene comprises between about 4 and 15% by weight of the outer layers.
Claim 4
Dependent Claim
17 words
The film according to claim 1 wherein polypropylene comprises about 8% by weight of the outer layers.
Claim 5
Dependent Claim
32 words
The film according to claim 1 wherein the film has been oriented by racking at a racking ratio of from about 3.0 to about 4.0 in both the longitudinal and transverse directions.
Claim 6
Dependent Claim
28 words
The film according to claim 1 wherein the film has been oriented by racking at a racking ratio of about 3.5 in both the longitudinal and transverse directions.
Claim 7
Dependent Claim
25 words
The film according to claim 1 wherein the ethylene propylene copolymer of the outer layers comprises between 2% and 5% by weight of ethylene comonomer.
Claim 8
Dependent Claim
23 words
The film according to claim 1 wherein the ethylene propylene copolymer of the outer layers comprises about 4% by weight of ethylene comonomer.
Claim 9
Dependent Claim
23 words
The film according to claim 1 wherein the ethylene propylene copolymer of the outer layers comprises about 5% by weight of ethylene comonomer.
Claim 10
Dependent Claim
19 words
The film according to claim 1 having longitudinal and transverse free shrink of at least 17% at 200° F.
Claim 11
Dependent Claim
18 words
The film according to claim 1 wherein the total film thickness ranges from about 0.5 to 2 mils.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |